In the prior art, various removal devices have been developed. WO2011/037465 discloses a removal device 10 with a main flow channel 22 defined by plates 20 placed transverse to the main flow direction within the inner space 18 of the housing 12, see FIG. 1 of WO2011/037465. The main flow channel 22 extends from the entry 14 to the exit 16, where near the exit 16 an end plate 50 is placed, transverse to the direction of the main flow channel 22, with a constricted opening 52. An upper quiet zone 44 and a lower quiet zone 48 are located in the upper and lower region of the inner space 18 respectively. In the upper quiet zone 44 and the lower quiet zone 48, the flow velocity is substantially lower than the velocity of the main flow 58. This lower velocity allows the rising of gas particles and the settling of dirt particles in the upper quiet zone 44 and the lower quiet zone 48 respectively.
The end plate 52 creates a pressure drop over the end plate 52 in the main flow in the main flow channel 22. This urges parts of the main flow to branch off between the plates 20. The branch flows flow upwards and downwards to the respective quiet zones 44 and 48. From the quiet zones 44 and 48, return flows 64 and 66 flow towards a merge point 68 located in a return flow channel behind the end plate 50 and near the exit 16.
The removal device according to WO2011/037465 is specifically suitable for certain sizes. It was found to be less effective to simply scale up the removal device of WO2011/037465 in order to obtain a removal device of a greater size.
US2008/0110344 discloses a de-aeration device which is rather primitive.
It was found that in general, removal devices which are known in the prior art have disadvantages. The efficiency of removal of dirt and/or gas particles is lower than desired. Moreover, the resistance to flow is higher than desired.
Known removal devices are also not very well capable of removing a liquid from another liquid. In particular, removing traces of an undesired volatile liquid from a base liquid is not very well performed by known removal devices.